An apparatus for conveying articles of clothing supported on hangers is shown in U.S. Pat. No. 4,239,435, dated Dec. 16, 1980, to Weiss et al. (the disclosure of which is hereby incorporated by reference), which discloses a sorting conveyor used to sort articles of clothing for delivery to customers. The sorting conveyor is made up of an endless chain with a plurality of carrier assemblies. Each carrier assembly includes several latch receptacles having a releasable latch mechanism adapted to support the hooked end of a hanger within the receptacle. The articles of clothing are sorted after being placed on the conveyor line by engaging the hooked end of each hanger in a latch receptacle of a carrier assembly.
In order to load hangers onto the conveyor, a single hanger must be placed on a loading ramp which raises the hanger into the carrier latch as the carrier moves into the proper receiving position by the loading ramp. Each hanger must be presented to the load ramp at a rate comparable to the arrival rate of available locations on the conveyor. The conveyor can move at a rate up to one hundred (100) feet per minute (FPM).
Since the garments on the hangers are to be sorted, and have been identified in a queue before being presented to the loader, the loader must be able to track the hangers and unambiguously identify a hanger and the corresponding conveyor location where it is latched.
To allow the use of multiple loaders, when the loader has paused, garments on the loader must not interfere with garments already on the conveyor. To prevent this interference, one solution is to provide a single hanger metering device, known as a "Singulator," to present one hanger to the loading ramp for each carrier assembly. For a typical carrier assembly length of one foot, this would require one garment to be released to the load ramp every 0.6 seconds. This release must be synchronized with the conveyor movement. Placing a hanger metering device such as the Singulator far enough away from the conveyor to allow garments to pass induces a large amount of uncertainty in the transit time of garments from the metering device to the load ramp, interfering with the synchronization of the hanger release with the arrival of available locations on the conveyor. Further, the expected slide time of a hanger with a garment is in excess of the 0.6 seconds required to fill every conveyor location. This introduces unwanted inefficiency into the loading process, as available conveyor locations arrive and pass too quickly to fill. In other words, the use of a single hanger metering device with a positive feedback upon successful insertion of the hanger into a carrier would make it impossible to load every conveyor location.
In addition, previous loaders require operator involvement to load garments into empty carrier positions. Other types require an upward moving part to load the hanger into the empty carrier. Both of these types of loaders introduce inefficiencies into the process. Coordinating two different moving parts (i.e., the conveyor and the loader) so that they arrive in the same place at the same time is a much more complex problem than simply controlling the movement of a single part, i.e., the conveyor. One solution requires stopping movement of the conveyor while the loader is moved upward. In addition to the inefficiency of pausing, the continual stopping and starting of the conveyor places an unnecessary strain on the mechanical system.
The present invention is therefore directed to the problem of developing a method and apparatus of the type mentioned at the outset in which every available conveyor location can be filled with a hanger during the loading process yet which does not impact the conveyor rate. The present invention is also directed to the problem of developing an apparatus for loading hangers on empty carriers passing the loader without requiring operator involvement, without requiring a moving loader, and without requiring the conveyor to pause while passing the loader.